Analysis of the Steady state performance of doubly fed induction machines

Abstract

This paper discusses the steady state maximum and minimum torque outputs and the operation at unity power factor of the doubly fed twin stator induction machine and the doubly fed induction machine using equations with analytical solutions. Speeds above and below the natural or synchronous speed are discussed. The results of simulations, based on a laboratory machine comprising two nominally identical wound rotor induction machines, are presented. It is shown that the maximum torque for the doubly fed machine is independent of speed and for the doubly fed twin stator induction machine there are variable maxima and minima dependent on speed.